<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    // screen   => window.screen 
    // availWidth /availHeight  屏幕的宽高 (不包含任务栏)
    // width /height  屏幕的宽高 (包含任务栏)
    console.log(screen);

    console.log(devicePixelRatio); // 设备的缩放比例
</script>
</html>